By giving hundreds of workers each a powerful desk-sized Alto minicomputer for their own needs, with a high-end graphical display, they gained insight into what desktop personal computing would look like 15 years later, enough insight to shape it profoundly. It's been 55 years, and although multitouch screens are proliferating, I'm still typing this on a keyboard hooked up to a framebuffer-driven display with a mouse hooked up to it, displaying hypertext, festooned with windows, icons, and a mouse that moves an onscreen pointer at the same 135° angle they settled on 55 years ago, positioning a vertical line to indicate the insertion point, with scrollbars. The display has twice as many pixels, the pixels are color, the mouse pointer is white rather than black, the screen is a flat LCD, the scrollbars are on the right, and the cursor blinks, but it's very recognizably descended from https://smalltalkzoo.computerhistory.org/HOPL-St78.html rather than, for example, ITS or GENESYS.

Only people with the luxury of unlimited zero-cost CPU cycles had a chance of seeing what the future looked like, and that allowed them to find out what worked and what didn't work in that environment. Nowadays, the regular workers who don't have the luxury of unlimited zero-cost tokens are manually reviewing voluminous AI code, because, even though that's a lot of slow work, they're still much faster programming that way than they were without it. Anthropic, instead, is doing insane things like eliciting a billion lines of Lean proofs to show that existing open-source libraries can't fail their OSS-FUZZ tests — and fixing all the bugs that effort turned up, in the process.